Light-emitting device and method of manufacturing the same

ABSTRACT

A method of manufacturing a light emitting device that includes a plurality of light emitting parts is provided. The method includes providing a base member having a plurality of recesses; mounting at least one light-emitting element in each of the plurality of recesses; disposing a light-transmissive layer continuously covering the plurality of recesses; and removing portions of the light-transmissive layer on the lateral wall between adjacent recesses to expose corresponding portions of the lateral wall, to obtain a plurality of light-transmissive members.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2016-088286 filed on Apr. 26, 2016, the entire disclosure of which ishereby incorporated by reference.

BACKGROUND

Technical Field

The present disclosure relates to a light-emitting device and a methodof manufacturing the device.

Description of Related Art

Light-emitting devices, which have a light-emitting diode (LED) mountedin a recess defined in a base member and a light-transmissive resindisposed over the recess, are known. See, for example, JapaneseUnexamined Patent Publications No. 2009-117536, No. 2013-219260, No.2012-54533, No. 2000-183405, No. 2009-122503, and No. H9-6259. Thelight-emitting devices disclosed in Japanese Unexamined PatentPublications No. 2009-117536 and No. 2013-219260 are intended to be usedmainly for lighting, and the light-emitting devices disclosed inJapanese Unexamined Patent Publications No. 2012-54533, No. 2000-183405,No. 2009-122503, and No. H9-6259 are intended to be used mainly fordisplays.

SUMMARY

In recent years, higher definition has been required in large-sizedisplays such as street displays.

Accordingly, it is an object of the present disclosure to provide alight-emitting device suitable for use in a high-definition displaydevice and the like, and also to provide a method of manufacturing sucha device.

A method of manufacturing a light emitting device having a plurality oflight emitting parts according to certain embodiments of the presentdisclosure includes: providing a base member defining a plurality ofrecesses each defined by a bottom surface and lateral surfaces that arerespectively inner lateral surfaces of a lateral wall separatingadjacent recesses; mounting at least one light-emitting element in eachof the plurality of recesses; forming a light-transmissive layercontinuously covering the plurality of recesses; and at least partiallyremoving portions of the light-transmissive layer on the lateral wallbetween adjacent recesses to expose at least portions of the lateralwall to form a plurality of light-transmissive members.

A light-emitting device having a plurality of light emitting partsaccording to certain embodiments of the present disclosure includes abase member having a plurality of recesses each defined by a bottomsurface and lateral surfaces that are inner lateral surfaces of alateral wall separating adjacent recesses at least one light-emittingelement mounted in each of the plurality of recesses, and a plurality oflight-transmissive members each having a flat upper surface and coveringrespective one of the plurality of recesses. The plurality oflight-transmissive members are separated from each other by the lateralwall separating adjacent recesses, and the upper surface of each of theplurality of light-transmissive members is located higher than anuppermost portion of the lateral wall.

The present disclosure provides a light-emitting device suitable for usein a high-definition display device and the like, and also to provide amethod of manufacturing such a device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic plan view illustrating a light-emitting deviceaccording to a first embodiment of the present disclosure.

FIG. 1B is a schematic cross-sectional view taken along line Z-Z shownin FIG. 1A.

FIGS. 2A, 2B, and 2C are schematic cross-sectional views of thelight-emitting device according to the first embodiment.

FIG. 3 is a schematic cross-sectional view illustrating a light emittingpart of the light-emitting device according to the first embodiment.

FIGS. 4A, 4B, 4C, 4D, 4E, and 4F are schematic plan views illustrating amethod of manufacturing the light-emitting device according to the firstembodiment.

FIG. 5A is a schematic cross-sectional view taken along line A-A of FIG.4A.

FIG. 5B is a schematic cross-sectional view taken along line B-B of FIG.4B.

FIG. 5C is a schematic cross-sectional view taken along line C-C of FIG.4C.

FIG. 5D is a schematic cross-sectional view taken along line D-D of FIG.4D.

FIG. 5E is a schematic cross-sectional view taken along line E-E of FIG.4E.

FIG. 5F is a schematic cross-sectional view taken along line F-F of FIG.4F.

FIG. 6 is a schematic cross-sectional view illustrating a variation of abase member for the light-emitting device according to the firstembodiment.

FIGS. 7A and 7B are schematic cross-sectional views illustrating amethod of manufacturing a light-emitting device according to a secondembodiment.

FIGS. 8A and 8B are schematic cross-sectional views illustrating amethod of manufacturing a light-emitting device according to a thirdembodiment.

FIGS. 9A and 9B are schematic cross-sectional views illustrating amethod of manufacturing a light-emitting device according to a fourthembodiment.

FIGS. 10A and 10B are schematic cross-sectional views illustrating amethod of manufacturing a light-emitting device according to a fifthembodiment.

FIGS. 11A and 11B are schematic cross-sectional views illustrating amethod of manufacturing a light-emitting device according to a sixthembodiment.

DETAILED DESCRIPTION

Embodiments of the present disclosure will now be described in detailwith reference to the accompanying drawings. In the description below,terms indicative of particular directions and locations, such as “up,”“down,” “right,” “left,” and other terms including any of these terms,will be used as needed. It should be noted that those terms are used foreasy understanding of the present disclosure with reference to theaccompanying drawings, and thus the technical scope of the presentdisclosure shall not be limited by the meaning of those terms. The samenumerals in different drawings indicate the same or similar portions ormembers.

The present disclosure provides a method of manufacturing a lightemitting device with simplified manufacturing steps, particularly in astep of forming a light-transmissive member, to achieve a reduction inthe cost of manufacturing. According to the present disclosure, alight-transmissive layer is formed to cover a plurality of firstrecesses defined in a base member, and then portions of thelight-transmissive layer are removed along lateral wall defining theplurality of first recesses. Thus, a plurality of light-transmissivemembers each covering respective one of the plurality of first recessescan be simultaneously formed.

In the description below, various exemplary configurations forlight-emitting devices will be described first, and then exemplarymanufacturing processes thereof will be described.

First Embodiment

FIG. 1A is a schematic plan view illustrating a light-emitting device 1according to a first embodiment of the present disclosure, and FIG. 1Bis a schematic cross-sectional view taken along line Z-Z of FIG. 1A.

The light-emitting device 1 includes a base member 20 having a pluralityof first recesses 30, light-emitting elements 50 mounted in each of theplurality of first recesses 30, and a plurality of light-transmissivemembers 40 each having a flat upper surface and covering respective oneof the plurality of first recesses 30. Adjacent light-transmissivemembers 40 are separated from each other by a lateral wall 26 betweenthe first recesses 30, and the upper surfaces of the light-transmissivemembers 40 are located higher than the uppermost portion of the lateralwall 26.

The base member 20 includes a substrate 25 providing portions eachdefining the bottom of each of the first recesses 30, and the lateralwall 26 formed on the upper surface of the substrate 25 and includinginner lateral surfaces defining lateral surfaces of each of the firstrecesses 30. The lateral wall 26 is arranged to separate the firstrecesses 30 from each other, and the inner lateral surfaces 26 c of thelateral wall 26 define lateral surfaces of each of the first recesses30. In the example shown in FIG. 1A, the light-emitting device 1 hasfour first recesses 31, 32, 33, and 34. The upper surface 25 a of thesubstrate 25 defines the bottom surfaces of the recesses 31, 32, 33, and34, and the inner lateral surfaces 26 c of the lateral wall 26 definelateral surfaces of each of the first recesses 31, 32, 33, and 34.

The substrate 25 may include a plate-shaped member 27 and wiringelectrodes 28 arranged on the upper surface thereof, for example. Whenthe substrate 25 includes the wiring electrodes 28, the upper surfaces28 a of the wiring electrodes 28 serve as parts of the upper surface 25a of the substrate 25.

At least one light-emitting element 50 is mounted in each of the firstrecesses 30. In the example shown in FIGS. 1A and 1B, a plurality oflight-emitting elements 50 are mounted in each of the first recesses,and three colors of light emitting elements: a red light-emittingelement 50R, a green light-emitting element 50G, and a bluelight-emitting element 50B are employed for the light emitting elements50. The red light-emitting element 50R has either positive electrode ornegative electrodes on the bottom or upper surfaces thereof,respectively. Either the positive or negative electrode is connected torespective corresponding wiring electrode 28 of the substrate 25, andthe other is connected to respective corresponding wiring electrode 28via a conductive wire 80. The green light-emitting element 50G and theblue light-emitting element 50B respectively have positive and negativeelectrodes on the upper surface thereof, and the electrodes areconnected to the wiring electrodes 28 via conductive wires 80,respectively.

The first recesses 30 are respectively covered by the light-transmissivemembers 40 which are separated from each other. The light-transmissivemembers 40 are filled in each of the first recesses 30 to cover thebottom surface and inner lateral surfaces of the lateral wall 26defining the first recess 30 and the light-emitting elements 50 mountedin the first recess 30. As shown in FIGS. 1A and 1B, thelight-transmissive member 41 covering the first recess 31 and thelight-transmissive member 42 covering the first recess 32 adjacent tothe first recess 31 are separated from each other by the lateral wall26.

As shown in FIG. 1A, the light-emitting device 1 is provided withgrooves 45 between adjacent light-transmissive members 40. The grooves45 are formed along the lateral wall 26, in an upper surface 40 a of thelight-transmissive member 40 to a depth reaching the upper surface 26 aof the lateral wall 26. In other words, at least portions of the bottomsurfaces defining the grooves 45 are the upper surface 26 a of thelateral wall 26.

As shown in FIGS. 1A and 1B, the light-emitting device 1 includes aplurality of light emitting parts 11, 12, 13, and 14, which may behereinafter collectively referred to as “light emitting part(s) 10”. Inthe present specification, each “light emitting part 10” includes, asits major components, a single first recess, at least one light-emittingelement mounted in the first recess, and the light-transmissive member40 covering the first recess. For example, the light emitting part 10includes the first recess 31, three light-emitting elements 50R, 50G,and 50B arranged in the first recess 31, and the light-transmissivemember 41 covering the first recess 31.

In FIG. 1B, the width 10 wof each light emitting part 10 corresponds tothe width of its light-transmissive member 40. This is because thelateral surfaces 40 c of the light-transmissive member 40 are located atthe outer sides with respect to the inner lateral surfaces 26 c of thelateral wall 26 that define each of the first recess 30. Thus, in thelight-emitting device 1, the interval 10 p between adjacent lightemitting parts 10 corresponds to the interval between adjacentlight-transmissive members 40, i.e., the width of the grooves 45.

As described above, the light-emitting device 1 includes a plurality offirst recesses 30. In each of the plurality of first recesses 30, atleast one light-emitting element 50 and the light-transmissive member40, etc., are arranged to constitute a single light emitting part. Whenthe light-emitting device 1 is used in a display device, a single lightemitting part can serve as a single pixel portion of the display device.That is, a single light-emitting device 1 can provide a plurality ofconstituent pixel portions of a display device. This allow for areduction in the number of light emitting devices to be arranged on amounting substrate, which in turn allows for a reduction in assemblycosts. Further, this also allows for arrangement of a plurality of lightemitting parts in close proximity to one another on a single basemember, which is appropriate for manufacturing a high-definition displaydevice.

In the example illustrated in FIGS. 1A and 1B, four light emitting partsare provided in a two-by-two array in a single light-emitting device 1,but five or more light emitting parts may be provided in the lightemitting device 1. In particular, when the light emitting device 1 isused in a display device the light-emitting device 1 preferably includesa plurality of light emitting parts arranged in a matrix of columns androws. It is more preferable that the number of columns and rows are apower of two, which may be 16×16, 16×32, 32×32, or 16×64, for example.

As shown in FIGS. 1A and 1B, the first recess 31 of the first lightemitting part 11 and the first recess 32 of the second light emittingpart 12 are separated from each other by the lateral wall 26 arrangedtherebetween. Thus, when the light-emitting elements 50 of the firstlight emitting part 11 are turned on, the light emitted from thelight-emitting elements 50 is blocked by the lateral wall 26 and notallowed to enter the first recess 32 of the second light emitting part12. In a similar manner, when the light-emitting elements 50 of thesecond light emitting part 12 are turned on, the light emitted from thelight-emitting elements 50 is blocked by the lateral wall 26 and hardlyenter the first recess 31 of the first light emitting part 11. That is,the use of a single light emitting part of the light-emitting device 1corresponding to a single pixel of a display image can reduce occurrenceof so-called “pseudo-lighting”, a phenomenon that occurs when one of twoadjacent pixel portions is in on-state and the other pixel portion is inoff-state, the pixel that is in off-state may appear to emit light.

The first light-transmissive member 41 of the first light emitting part11 and the second light-transmissive member 42 of the second lightemitting part 12 are separated from each other by the lateral wall 26.In other words, the first light-transmissive member 41 and the secondlight-transmissive member 42 are adjacent to each other with the lateralwall 26 therebetween. When the light-emitting elements 50 arranged inthe light-transmissive members emit light, each of thelight-transmissive members can serve as a light guide member that allowsthe light propagating therethrough. Thus, if the firstlight-transmissive member 41 and the second light-transmissive member 42were continuous with each other, light emitted from the light-emittingelements 50 of the first light emitting part 11 can propagate throughthe first light-transmissive member 41 to the second light-transmissivemember 42. In such a case, when the first light emitting part 11 isturned on, the second light emitting part 12 that is in off-state mayappear to emit light.

However, in the light-emitting device 1 of the present disclosure,groove 45 is formed between the first light-transmissive member 41 andthe second light-transmissive member 42. That is, the firstlight-transmissive member 41 and the second light-transmissive member42, which are located higher than the uppermost portion of the lateralwall 26, are separated from each other by the groove 45. With thisarrangement, when the light emitting elements 50 of the first lightemitting part 11 are turned on, propagation of the light from the firstlight-transmissive member 41 into the second light-transmissive member42 can be reduced. Accordingly, occurrence of pseudo-lighting can bereduced.

The groove 45 is formed with a depth reaching the upper surface of thelateral wall 26. In other words, at least a portion of the bottomsurface of the groove 45 is defined by the upper surface of the lateralwall 26. Accordingly, when the light-emitting device 1 is viewed from aviewing side, a portion of the upper surface 26 a of the lateral wall 26can be visually recognized at the bottom surface of the groove 45. As aresult, when the light-emitting device 1 is used in a display device,that is when the light-emitting device 1 is viewed from a viewing side,adjacent light emitting parts can be visually recognized as beingseparated from one another by the upper surfaces 26 a of the lateralwall 26. With this arrangement, stronger outlines of the light emittingparts can be obtained, thus increasing the sharpness of the image on thedisplay. With the lateral wall 26 of a dark color, e.g., a black color,a display image having a high contrast ratio can be obtained.

As shown in FIG. 1B, the upper surface 26 a of the lateral wall 26 maybe partially covered by the light-transmissive members 40. Under a humidenvironment, water may enter the light emitting device 1 from thegrooves 45 through interfaces between the lateral wall 26 and thelight-transmissive members 40, which may cause malfunction. However,when portions of the upper surface 26 a of the lateral wall 26 arepartially covered by the light-transmissive members 40, the distance ofwater entering the recesses 30 can be increased by the interfacesbetween the upper surfaces 26 a of the lateral walls 26 and thelight-transmissive members 40. With this configuration, the amount ofwater entering in the recesses 30 can be reduced, which in turn canreduce degradation of the light emitting device 1. Accordingly, a highlyreliable light-emitting device 1 with a longer operation life can beprovided.

The upper surfaces 40 a of the light-transmissive members 40 may havevarious shapes such as a protruded shape, a recessed shape, and a flatshape; of those, a flat shape is preferable. In the case where the uppersurfaces 40 a are formed in a flat shape, a plurality oflight-transmissive members 40 of the light emitting device 1 can beformed through a simple process while obtaining the upper surfaces 40 aof the light-transmissive members 40 with a tighter range of tolerancein terms of dimension and shape.

For example, filling the first recesses 30 with the light-transmissivemember 40 in the first recesses 30 is carried out by applying a liquidresin material of the light-transmissive members 40 dropwise into thefirst recesses 30 and then curing the liquid resin material. In thiscase, when a larger drop of the liquid resin material is applied, thesurface tension of the liquid resin material causes its surface tobulge, so that upon curing, a bulged upper surface 40 a can be obtained.Meanwhile, when a smaller drop of the liquid resin material is applied,the liquid resin material raises up along the lateral surfaces definingthe first recess 30, so that upon subsequent curing, a concaved uppersurface 40 a can be obtained.

The shape and dimensions of the upper surface 40 a may vary easily witheven a slight fluctuation in the dropping amount of the liquid resinmaterial, and/or with a slight variation in the characteristics of thesurfaces defining the first recesses 30. That is, a slight change in thewettability of the liquid resin material with respect to the lateralsurfaces defining the first recesses 30 may cause a variation in thedimensions and shapes of the upper surfaces 40 a, which may lead tovariation in the directivity of light of the plurality of light emittingparts 10 in the light emitting device 1.

Examples of methods to form the light transmissive members 40 havingprotruded upper surfaces or concaved upper surfaces include filling thefirst recesses 30 with the light-transmissive material using a moldassembly. In this case, precise positioning is required so that thecenters of the first recesses 30 and the corresponding centers of themold assembly are accurately aligned.

In contrast, when forming the light transmissive members 40 having flatupper surfaces 40 a, a flat mold can be used, which does not requireprecise positioning of the centers of the first recesses 30 and thecorresponding portions of the mold. Further, the use of a mold assemblycan eliminate occurrence of variation in the shapes and dimensions ofthe upper surfaces 40 a that may occur when the liquid resin material isapplied by dropping. Thus, forming the upper surfaces 40 a of thelight-transmitting members 40 of the light-emitting device 1 into a flatshape allows simplifying the manufacturing steps and reduction ofvariation in the optical directivity of the light-emitting devices 1. Inparticular, when the light emitting device 1 is used for a display,small variation in the optical directivity of the light emitting parts10 allows for obtaining a display having small unevenness in theluminance and color.

In the present specification, the term “flat” refers to a conditionwhere protrusions and/or recesses that can significantly affect thedirectivity of light (mainly in terms of viewing angle) are absent. Inthis regard, presence of minute protrusions and/or recesses formed bysurface roughening or the like can be assumed “flat” in the presentspecification, unless it causes a significant change in the opticaldirectivity. More specifically, a surface with a surface roughness Ra of10 μm or less does not practically affect the directivity of light, sothat it can be assumed flat. When the light-emitting device 1 is usedfor a display, roughening the upper surfaces 40 a (for example, to asurface roughness Ra in a range of 1 to 10 μm) can reduce generation ofglare (lights).

If an upper surface 50 a (see FIGS. 2A to 2C) of at least one of thelight-emitting elements 50 is located higher than the upper surfaces 26a of the corresponding lateral wall 26, the viewing angle increases, butif the upper surface 50 a of the light-emitting element 50 is locatedsignificantly higher than the upper surfaces 26 a of the correspondinglateral wall 26, light-blocking effect of the lateral wall decreases andpseudo-lighting may occur. If the upper surface 50 a of at least one ofthe light-emitting elements 50 is located lower than the upper surfaces26 a of the corresponding lateral wall 26, the light-blocking effect ofthe lateral wall 26 increases, but if the upper surface 50 a of thelight-emitting element 50 is located significantly lower than the uppersurfaces 26 a of the corresponding lateral wall 26, the viewing angledecreases. Thus, in order to obtain a good balance of the light-blockingeffect and the viewing angle, it is preferable that the heights of theupper surfaces 50 a of the light emitting elements 50 are notsignificantly different from the heights of the upper surfaces 26 a ofthe lateral wall 26.

In order to determine the difference in the height of the upper surfaces50 a of the light-emitting elements 50 and the upper surfaces 26 a ofthe lateral wall 26, a tangent line is assumed by the upper surface 50 aof one of the light emitting elements 50 and the upper surface 26 a ofone of the lateral wall 26. More specifically, the angle formed by thetangent line and the upper surface 25 a of the substrate 25 (hereinafterreferred to as the “tilt angle of the tangent line”) is used. Now withreference to FIGS. 2A to 2C, tangent lines passing through respectivepoints on the upper surface 50 a of the light emitting element 50 andpoints on the upper surfaces 26 a of the lateral wall 26, and thecorresponding tilt angles of the tangent lines will be described.

FIGS. 2A, 2B, and 2C are schematic cross-sectional views each showingone of the light emitting parts 10 included in the light-emitting device1.

In each of the cross-sectional views shown in FIGS. 2A to 2C, the uppersurface 50 a of the light emitting element 50 has an edge 50 e ₁ (aproximate edge 50 e ₁) proximate to the lateral wall 26 and an edge 50 e₂ (distal edge 50 e ₂) distal to the lateral wall 26, and the uppersurfaces 26 a of the lateral wall respectively have an edge 26 e ₁distal to the light emitting element 50 and an edge 26 e ₂ proximate tothe light emitting element 50.

In the light emitting part 10 shown in FIG. 2A, the upper surface 50 aof the light-emitting element 50 is substantially flush with the uppersurfaces 26 a of the lateral wall 26. In this example, a straight linepassing through the upper surface 50 a of the light-emitting element 50and the upper surfaces 26 a of the lateral wall 26 is indicated as(defined as) the tangent line L₁. Since the tangent line L₁ is parallelto the upper surface 25 a of the substrate 25, the angle formed by thetangent line L₁ and the upper surface 25 a (i.e., tilt angle of thetangent line) is 0°. Accordingly, the light emitting part 10 has aviewing angle α of 180°.

In the light emitting part 10 shown in FIG. 2B, the upper surface 50 aof the light-emitting element 50 is located higher than the uppersurfaces 26 a of the lateral wall 26. In this example, a tangent line L₂is a straight line passing through a point on the proximate edge 50 e ₁of the upper surface 50 a of the light-emitting element 50 and a pointon the distal edge 26 e ₁ of the upper surface 26 a of the lateral wall26. The tangent line L₂ slopes down outward. The angle formed by thetangent line L₂ and the upper surface 25 a (i.e., tilt angle of thetangent line) is θ₁. The viewing angle α of the light emitting part 10is 180°+2×θ₁. In this example, the lateral wall 26 have a small height,which may lead to insufficient blocking of light, in other words, maycause pseudo lighting in an adjacent light emitting part 10.

In the light emitting part 10 shown in FIG. 2C, the upper surface 50 aof the light-emitting element 50 is located lower than the uppersurfaces 26 a of the lateral wall 26. In this example, a tangent line L₃a straight line passing through a point on the distal edge 50 e ₂ of theupper surface 50 a of the light-emitting element 50 and a point on theproximate edge 26 e ₂ of the upper surface 26 a of the lateral wall 26.The tangent line L₃ slopes upward. The angle formed by the tangent lineL₃ and the upper surface 25 a (i.e., tilt angle of the tangent line) isθ₂. The viewing angle α of the light emitting part 10 is 180°−2×θ₂. Inthis example, the lateral wall 26 have a large height, which may lead toa reduction in the directivity. That is, when applied to a display,visibility from an oblique direction may be reduced.

In a cross-sectional view of the light emitting part 10 as shown in FIG.2B, it is preferable that the angle θ₁ be in a range of 0° to 5°,because the decrease in the blocking of light due to the height of thelateral wall 26 can be reduced, and thus occurrence of pseudo-lightingcan be reduced. Meanwhile, in a cross-sectional view of the lightemitting part 10 as shown in FIG. 2C, when the angle θ₂ is in a range of0° to 5°, a wide viewing angle α of 170° or greater can be achieved thatallows for manufacturing of displays with wide viewing angles. That is,in a cross sectional view of the light emitting device, when an angleformed by a tangent line passing a point on the upper surface 26 a ofthe lateral wall 26 and a point on the upper surface 50 a of the lightemitting element 50 and the upper surface 25 a of the substrate 25(i.e., tilt angle of the tangent line) is in a range of 0° to 5°, thelight emitting device having a good balance of the viewing angle and thelight-blocking properties can be obtained.

In the examples shown in FIGS. 2A to 2C, tangent lines are determinedwith respect to a single light emitting part 10 that includes a singlelight-emitting element 50. When the single light emitting part 10includes a plurality of light-emitting elements 50, the tangent line isdetermined for each of the light-emitting elements 50, preferably with atilt angle of 5° or less. When the plurality of light-emitting elements50 has different heights, the tangent line can be determined for ahighest light emitting element 50, with the tilt angle of 5° or less,which allows for obtaining an extended definition display device withreduced pseudo-lighting.

The upper surfaces 40 a of the light-transmissive members 40 are locatedhigher than the uppermost portion 26 t of the lateral wall 26. In otherwords, the light-transmissive members 40 protrude from the firstrecesses 30. In the present specification, the term “uppermost portion26 t of lateral wall 26” refers to a highest portion of the lateral wall26 with reference to the upper surface 25 a of the substrate 25. Whenthe upper surfaces 26 a of the lateral walls 26 are flat as shown inFIG. 1B, the uppermost portion 26 t corresponds to the entire uppersurface 26 a.

The portions of the light-transmissive members 40 protruding withrespect to a plane including the upper surfaces 26 a of the lateralwalls 26 can contribute to directing the light emitted from thelight-emitting element 50 to the outside of the first recesses 30. Inparticular, when the light-emitting device 1 is used for a display, theviewing angle of the display can be increased by the protrudingportions.

As shown in FIG. 3, the light-emitting elements 50 may be semiconductorlight-emitting elements having a first conductivity-type semiconductorlayer 51, an active layer 52, and a second conductivity-typesemiconductor layer 53 layered in this order. The firstconductivity-type semiconductor layer 51 may be, for example, an n-typesemiconductor layer, and the second conductivity-type semiconductorlayer 53 may be, for example, a p-type semiconductor layer.

The light emitted from the active layer 52 has a higher intensity than,for example, the light propagated through the light-transmissive member40. It is, therefore, of significance that the light emitting parts arenot directly irradiated by the light emitted from the active layers 52of adjacent light emitting parts. Thus, the heights 26 h of thesidewalls 26 are preferably appropriately greater than the heights 52 hof the active layers 52 of the light-emitting elements 50.

In the present specification, the term “height 26 h of the lateral wall26” refers to the height of the uppermost portion 26 t of the lateralwall 26 from the upper surface 25 a of the substrate 25. When thelateral wall 26 has a flat upper surface 26 a, the height 26 h of thelateral wall 26 is the height of the upper surface 26 a of the lateralwall 26 from the upper surface 25 a of the substrate 25. Also, the term“height 52 h of the active layer 52” refers to the height of the highestportion of the active layer 52 from the upper surface 25 a of thesubstrate 25.

When the height 26 h of the lateral wall 26 is greater than the heights52 h of the active layers 52 of the light-emitting elements 50 (in otherwords, the uppermost portion 26 t of the lateral wall 26 is locatedhigher than the active layers 52 of the light-emitting elements 50),light emitted from the active layers 52 of the light emitting elements50 in the lighting part 10 can be prevented from directly entering therecesses 30 of the light emitting parts 10 of adjacent light emittingparts 10. Accordingly, when the light emitting device 1 is used for adisplay, occurrence of pseudo-lighting can be reduced.

When a single light emitting part 10 includes a plurality oflight-emitting elements 50 of different emission colors, the lightemitting elements 50 may have active layers 52 of different heights 52h, respectively. In this case, the uppermost portion 26 t of the lateralwall 26 is preferably located higher than any of the active layers 52 ofthe light-emitting elements 50. With this configuration, the shieldingeffect of the lateral wall 26 can be improved. For example, in theexample illustrated in FIG. 3, a single light emitting part 10 includesthree light-emitting elements 50R, 50G, and 50B, and the uppermostportion 26 t of the lateral wall 26 are located higher than any of theactive layers 52.

Next, an exemplary method of manufacturing such a light-emitting devicewill be described with reference to FIGS. 4A to 4F, and FIGS. 5A to 5F.

Providing Base Member 20

In a step of providing a base member 20, a base member defining aplurality of first recesses 30 is provided. The step of providing thebase member 20 includes providing a substrate 25, and forming a lateralwall 26 on an upper surface 25 a of the substrate 25.

Providing Substrate 25

As shown in FIG. 4A and FIG. 5A, wiring electrodes 28 (indicated byhatches in FIG. 4A) are formed in a predetermined pattern on an uppersurface of a plate-shaped member 27 to provide the substrate 25.

The plate-shaped member 27 is preferably made of an insulating material,which preferably allows little of the light emitted from the lightemitting elements 50 and/or external light to pass therethrough.Specific examples of such materials include ceramics made of aluminumoxide, aluminum nitride, zirconium oxide, zirconium nitride, titaniumoxide, titanium nitride, or a mixture of two or more of those; resinmaterials such as epoxy resins, BT resins, polyimide resins; and fiberreinforced resins of those resins (including glass or alumina as areinforcing material). Among those, glass epoxy is often used as a basematerial for the base member of a printed circuit board for mountingelectronic elements, and is much less expensive than ceramics andmetals. Also, glass epoxy has superior electrical properties and thermalproperties to paper phenol that is frequently used for similar purposes,and is suitably used as a base material for the base member of asemiconductor device.

The wiring electrodes 28 may be made of an electrically conductivematerial, e.g., a metal such as gold, silver, copper, nickel, palladium,tungsten, chromium, titanium, aluminum, iron, tin, platinum, or rhodium,or an alloy thereof. Among those, copper or a copper alloy is preferablein view of heat dissipating performance. The wiring electrodes 28 mayeither be made of a single layer or two or more layers.

Forming Lateral Wall 26 on Upper Surface 25 a of Substrate 25

Next, as shown in FIG. 4B, a lateral wall 26 is formed in a latticeshape in a plan view on the upper surface 25 a of the substrate 25, toobtain the base member 20. Preferable examples of materials for thelateral wall 26 include a silicone resin, an epoxy resin, a modifiedsilicone resin, a modified epoxy resin, a polyimide resin, a modifiedpolyimide resin, polyphthalamide (PPA), polycarbonate,polyphenylenesulfide (PPS), unsaturated polyester, a liquid crystalpolymer (LCP), an ABS resin, a phenol resin, an acrylic resin, and a PBTresin. The lateral wall 26 is preferably made of a material having a lowreflectance to external light such as sunlight, and preferably has adark color (such as black or a nearly black color). When the lightemitting device 1 is used as a single pixel of a display, the lateralwall 26 of black color or a nearly black color allows an increase in thecontrast ratio of the display. The lateral wall 26 of such a dark colorcan be obtained by appropriately adding carbon black, a pigment,titanium oxide, silicon dioxide, zirconium oxide, potassium titanate,alumina, aluminum nitride, boron nitride, mullite, or the like to any ofthe resins described above.

The lateral wall 26 may be formed by way of a potting method, in which,through a dispenser, an uncured liquid resin material is applied in apredetermined pattern (e.g., in a lattice pattern) onto the uppersurface 25 a of the substrate 25. The lateral wall 26 may also beformed, for example, by injection molding with the use of a mold havingrecesses corresponding to the shape of the lateral wall 26 placed on theupper surface 25 a of the substrate 25.

As described above, providing the lateral wall 26 on the upper surfaceof the substrate 25 allows the plate-shaped member 27 of the substrate25 and the lateral wall 26 to be made of different materials. In otherwords, suitable materials can be used for the lateral wall 26 and theplate-shaped member 27, respectively. For example, a plate-shaped member27 made of a glass epoxy resin having good electrical and thermalresistance properties can be used in combination with lateral wall 26made of a dark-colored resin material appropriate for a wall.

With the lateral wall 26 provided on the substrate 25, at least onefirst recess 30 can be defined in the base member 20, by a bottomsurface of exposed portion of the upper surface 25 a and the innerlateral surfaces 26 c of the lateral wall 26 as shown in FIG. 5B. Thelateral wall 26 is provided such that the wiring electrodes 28 on theupper surface 25 a of the substrate 25 are at least partially exposed atthe bottom of the first recess 30. A single base member 20 may define asingle first recess 30 or a plurality of first recesses 30, butpreferably has a plurality of first recesses 30. For example, the basemember 20 shown in FIG. 4B has four first recesses 30, in which twoadjacent first recesses 30 are preferably separated from each other by aportion of the lateral wall 26. That is to say, it is preferable thatthe lateral wall 26 defining the first recesses 30 also serve as thelateral wall 26 demarcating adjacent first recesses 30. In other words,a portion of lateral wall 26 defines respective portions of two adjacentfirst recesses, which allows a reduction in the spacing between theadjacent recesses 30. Accordingly, the use of the light emitting device1 that employs the base member 20 for a display allows for a reductionin the spacing of the pixels, that in turn can contribute to obtaining adisplay that can display high-definition images.

Variation of Base Member

When the plate member 27 and the lateral wall 26 are made of the samematerial as shown in FIG. 6, the plate-shaped member 27 and the lateralwall 26 can be formed at the same time. For example, the plate-shapedmember 27 and the lateral wall 26 can be formed by injection molding orthe like, in which a lead frame is used as the material of the wiringelectrodes 28, and portions of the lead frame corresponding torespective wiring electrodes 28 are interposed between upper and lowermolds defining recesses corresponding to respective shapes of theplate-shaped member 27 and the lateral wall 26.

Forming the plate member 27 and the lateral wall 26 at the same time cansimplify the manufacturing process and also can increase the bondingstrength between the plate member 27 and the lateral wall 26.

Mounting Light-Emitting Elements 50 on Base Member 20

As shown in FIG. 4C and FIG. 5C, at least one light-emitting element 50is mounted on the bottom of each of the first recesses 30 defined in thebase member 20. In the example illustrated in FIG. 4C and FIG. 5C, threelight-emitting elements 50 are mounted on each first recess 30.

As described above, at least portions of the wiring electrodes 28disposed on the upper surface 25 a of the substrate 25 are arranged onthe bottom of each first recess 30, so that each of the light-emittingelements 50 can be mounted on corresponding portions of the wiringelectrodes 28. With this configuration, for example, a light-emittingelement 50 having an electrode on its lower surface, such as each of thered light-emitting elements 50R shown in FIG. 4C, can be electricallyconnected to corresponding wiring electrode 28. A light-emitting element50 which does not have an electrode on its lower surface, such as eachof the blue light-emitting elements 50B and green light-emittingelements 50G shown in FIG. 4C, is also preferably mounted on the wiringelectrode 28. Mounting the light-emitting elements 50 on the wiringelectrode 28 allows efficient dissipation of the heat generated by thelight-emitting elements 50 in light-on state through the wiringelectrode 28.

A light-emitting element 50 having an electrode on its upper surface hasthe electrode electrically connected via electrically conductive wires80 to the respective wiring electrodes 28 exposed at the bottom of therecess 30. As described above, the light-emitting elements 50 can beelectrically connected to the wiring electrodes 28, respectively. InFIG. 4C, each of the red light-emitting elements 50R has a singleelectrode on its upper surface, and each of the green light-emittingelements 50G and blue light-emitting elements 50B has two electrodes onits upper surface. The electrically conductive wire 80 may be made of ametal such as Au, Ag, Cu or Al or an alloy whose main component is oneor more of those metals.

The light-emitting elements 50 may each include a first-conductivitytype semiconductor layer 51 (e.g., n-type semiconductor layer), anactive layer 52, and a second-conductivity type semiconductor layer 53(e.g., p-type semiconductor layer), as shown in FIG. 3. Thelight-emitting elements 50 can be made of semiconductor materials suchas a Group III-V compound semiconductor, and a Group II-VI compoundsemiconductor. More specifically, the red light-emitting elements 50Rmay be made of a compound semiconductor material such as GaAlAs orInAlGaP. The green light-emitting elements 50G and blue light-emittingelements 50B may be made of a nitride compound semiconductor materialsuch as In_(X)Al_(Y)Ga_(1−X−Y)N (where 0≤X, 0≤Y, and X+Y≤1). Examples ofsuch nitride compound semiconductor materials include InN, AlN, GaN,InGaN, AlGaN, and InGaAlN.

Forming Light-Transmissive Layer 400

After mounting the light-emitting elements 50 in each of the pluralityof first recesses 30 of the base member 20, a light-transmissive layer400 is disposed to continuously cover the plurality of the firstrecesses 30. The light-transmissive layer 400 is configured to be formedinto a plurality of the light-transmissive members 40 of thelight-emitting device 1 (see FIG. 1B).

The light-transmissive layer 400 is disposed to cover the light-emittingelements 50 in the first recesses 30, the bottom of each of the firstrecesses 30 (i.e., the upper surface 25 a of the substrate 25), theinner lateral surfaces 26 c of the lateral wall 26, and the uppersurfaces 26 a of the lateral wall 26. The light-transmissive layer 400preferably has a flat upper surface 400 a, which is preferably locatedhigher than the uppermost portion 26 t of the lateral wall 26 (in FIG.5D, the uppermost portion 26 t of the lateral wall 26 is in the uppersurfaces 26 a of the lateral wall 26).

The light-transmissive layer 400 may be formed, for example, using amold (assembly), as described below. As shown in FIG. 5C, a mold 70 witha flat surface 70 b is placed over the base member 20 having thelight-emitting elements 50 mounted thereon. At this time, the mold 70 isarranged spaced apart from the uppermost portion 26 t of the lateralwall 26. With this arrangement, when a light-transmissive material isinjected between the mold 70 and the base member 20, thelight-transmissive material is allowed to cover the uppermost portion 26t of the lateral wall 26 and also allows the upper surface 400 a of theresulting light-transmissive layer 400 to be located above the uppermostportion 26 t of the lateral wall 26. Strict positioning between the mold70 and the base member 20 is not necessary in the use of a mold 70having a flat surface 70 b. Thus, the occurrence of faulty products dueto insufficient positioning between the mold 70 and the base member 20can be reduced.

The mold 70 may have roughened surface 70 b, to obtain the upper surface400 a, with which the upper surface 400 a of the light-transmissivelayer 400 (FIG. 5D), that is, the upper surface 40 a of thelight-transmissive member 40 of the light emitting device 1, can beroughened. The surface roughness Ra of the surface 70 b of the mold 70is preferably 10 μm or less, and for example, a surface roughness Ra ina range of 1 μm to 10 μm can be employed.

For the light-transmissive layer 400, a resin material having a hightransmittance to the light emitted from the light-emitting elements 50may be used, which may either be a thermosetting resin or athermoplastic resin. In particular, the use of a thermosetting resinhaving good thermal resistance is preferable because it allows areduction in degradation of the light-transmissive members 40 caused bythe heat generated by the light-emitting elements 50 when lighting inthe light-emitting device 1 ready for use. Examples of suitablethermosetting resins include silicon resins, modified silicone resins,epoxy resins, and phenol resins.

In order to provide a desired physical property, an appropriate additivemay be included in the light-transmissive layer 400. For example, inorder to adjust the refractive index of the light-transmissive layer400, and/or to adjust the viscosity of the material of thelight-transmissive layer 400, various types of filler, for example, alight-scattering agent, may be included in the light-transmissive layer400. A light scattering agent of a large amount may cause a decrease inthe light extraction efficiency, but with a small amount, the lightextraction efficiency can be improved. The concentration of lightscattering agent added to the light-transmissive layer 400 may be in arange of about 5% to about 60% by mass. Examples of the light scatteringagent include aluminum oxide, silicon oxide, titanium oxide, and bariumsulfate. The examples also include a powder of a pigment, a fluorescentsubstance, or the like.

Partially Removing Light-Transmissive Layer 400

As shown in FIG. 4E and FIG. 5E, the light-transmissive layer 400 ispartially removed along the upper surface 26 a of the lateral wall 26between the first recesses 30. The partial removal of thelight-transmissive layer 40 may be carried out by cutting or the likewith the use of a blade or a laser beam, for example. More specifically,as shown in FIG. 4D and FIG. 5D, a portion of the light-transmissivelayer 400 that covers the upper surface 26 a of the lateral wall 26(hereinafter may be referred to as a “covering portion 400 x”) isremoved along the lines L11, L12, L13, L21, L22 and L23.

As described above, the upper surface 26 a of the lateral wall 26arranged between the plurality of first recesses 30 is covered by aportion of the light-transmissive layer 400. Removing the coveringportion 400 x of the light-transmissive layer 400 between the firstrecesses 30 forms the groove 45 in the light-transmissive layer 400. Thedepth of each portion of the groove 45 is set to expose the lateral wall26 at the bottom of the groove 45.

As described above, the light-transmissive layer 400 is divided into aplurality of light-transmissive members 40 by the groove 45 formed alongthe lateral wall 26 between the first recesses 30. That is, in the stepof partially removing the light-transmissive layer 400, the coveringportion 400 x, that is the portion of the light-transmissive layer 400on the lateral wall 26 arranged between the first recesses 30, isremoved to expose the lateral wall 26 between the first recesses 30, andthus a plurality of light-transmissive members 40 is formed.

At this time, a portion of the light-transmissive layer 400 on thelateral wall 26 at an outer periphery of the light emitting device 1 ispreferably also removed. That is, in a plan view, the lateral wall 26 ispreferably not covered by the light-transmissive layer 400 at the outerperiphery of the light-emitting device 1. Accordingly, when a pluralityof light emitting devices 1 is arranged to provide a display, clearoutlines of the light emitting parts located at the outer periphery ofeach light emitting device 1 can be obtained, thus increasing thesharpness of an image on the display. Thus, the light-emitting device 1is obtained.

Variation in the Partially Removing Light-Transmissive Layer 400

In the step of partially removing the light-transmissive layer 400, thecovering portion 400 x of the light-transmissive layer 400 may beremoved either partially or completely. In the present specification,the expression “partially removing” refers to removing a portion of thecovering portion 400 x in its width direction (i.e., the right and leftdirection in FIG. 5E).

In order to completely remove the covering portion 400 x, for example asshown in FIGS. 7A and 7B, a blade 93 having a blade width greater thanthe width 26 w of the lateral wall 26 may be used. The blade width ofthe blade 93 is greater than the width 26 w of the lateral wall 26 thatis the same width as the covering portion 400 x, so that the coveringportion 400 x can be completely removed by the blade 93.

As shown in FIG. 7A, the depth 93 d of the blade 93 in the coveringportion 400 x (i.e., the depth 45 sd of the groove 45 s in FIG. 7B) maybe greater than the thickness 400 d of the covering portion 400 x. Thatis, the blade 93 may remove the entire of the covering portion 400 xwith corresponding portion of the upper portion 26 a of the lateral wall26 to reduce the height 26 h of the lateral wall 26. As shown in FIG.7A, after removing the upper portion 26 a of the lateral wall 26, theheight 26 sh of the lateral wall 26 is smaller than the height 26 h ofthe lateral wall 26 before removing the upper portion 26 a (i.e., height26 sh<height 26 h). Thus, in the light-emitting device 2 shown in FIG.7B, the determination of the location of the upper surface 26 a of thelateral wall 26 shown in FIG. 2 and the determination of the height 26 hof the lateral wall 26 shown in FIG. 3 can also be applied to thelocation and the height 26 sh of the upper surface 26 sa of the lateralwall 26 s after removing the upper portion.

The example shown in FIGS. 7A and 7B can be efficient when the height 26sh of the lateral wall 26 in the light-emitting device 2 ready for useto be smaller than the height 26 h of the lateral wall 26 formed in thestep of providing the base member. For example, when the lateral wall 26s is disposed by potting using a dispenser or the like, difference inheight of the lateral wall 26 s may occur at, for example, anintersecting portion of the lateral wall 26 s in a plan view. Even insuch case, according to the present variation, the lateral wall 26 s ofapproximately same height can be provided in the light emitting deviceready for use.

In a plan view of the light-emitting device 2 shown in FIG. 7B, theupper surface 26 sa of the lateral wall 26 s can be seen at the bottomof each portion of the groove 45 s. As in described above, when thelight-emitting device 2 is used in a display device, adjacent lightemitting parts are seen separated by respective corresponding portionsof the upper surface 26 sa of the lateral wall 26 s. When a blade isused, a trace of the blade may be left in the upper surface 26 sa, inother words, the upper surface 26 sa is roughened. This configurationreduces reflection of external light at the upper surface 26 sa towardthe viewer, so that a display device of high contrast ratio can beprovided.

In FIG. 7B, the width 10 w of each light emitting part 10 corresponds tothe width 30 w of the first recess 30. Thus, the spacing 10 p betweenadjacent light emitting parts 10 corresponds to the width 26 sw of thelateral wall 26 s.

In order to partially remove the covering portion 400 x, for example asshown in FIG. 5E, FIG. 8A, and FIG. 9A, blades 90, 91, having bladewidths 90 w, 91 w, respectively smaller than the width 26 w of thelateral wall 26 may be used. The blade widths 90 w and 91 w of theblades 90 and 91, respectively, are smaller than the width 26 w of thelateral wall 26, where the width 26 w corresponds to the width of thecovering portion 400 x, thus allowing the partial removal of thecovering portion 400 x.

For example, as shown in FIG. 5E, a portion of the covering portion 400x (see FIG. 5D) covering the upper surface 26 a of the lateral wall 26is removed using the blade 90 to form a groove 45 in thelight-transmissive layer 400 (see FIG. 5F). The portions of the coveringportion 400 x that have not been removed (hereinafter may be referred toas “residual covering portions 40 x” of the light-transmissive member40) are allowed to be present on the upper surface 26 a of the lateralwall 26, defining both or either of the lateral sides of the grooves 45in the light-emitting device 1 ready for use (see FIG. 5F).

Unlike the example shown in FIG. 7A, in the example shown in FIG. 5E,the depth 90 d of the blade 90 (i.e., the depth 45 d of the groove 45 inFIG. 5F) is substantially equal to the thickness 400 d of the coveringportion 400 x. That is, only the covering portion 400 x is removed bythe blade 90 and the upper portion of the lateral wall 26 is notsubstantially removed. Thus, in the light-emitting device 1 as shown inFIG. 5E, the determination of the location of the upper surface 26 a ofthe lateral wall 26 shown in FIG. 2 and the determination of the height26 h of the lateral wall 26 as shown in FIG. 3 can also be applied.

The example shown in FIG. 8A is similar to that in the example shown inFIG. 5E except the depth 90 d of the blade 90. As shown in FIG. 8A, thecovering portion 400 x (see FIG. 5D) covering the upper surface 26 a ofthe lateral wall 26 is partially removed with the use of the blade 90 toform the grooves 45 x in the light-transmissive layer 400. The portionsof the covering portion 400 x that have not been removed (the residualcovering portions 40 x of the light-transmissive members 40) are allowedto be present on the upper surface 26 a of the lateral wall 26, definingboth or either of the lateral sides of the grooves 45 in the lightemitting device 3 ready for use (see FIG. 8B).

In the example shown in FIG. 8A, in a similar manner as in FIG. 7A, thedepth 90 d of the blade 90 (that is the depth 45 d of the groove 45 inFIG. 8A) is greater than the thickness 400 d of the covering portion 400x. The blade 90 may remove a portion the covering portion 400 x withcorresponding portion of the upper portion 26 a of the lateral wall 26to form a second recess 26 xd on the upper surface 26 a of the lateralwall 26. As shown in FIG. 8B, the upper surface 26 xa of the lateralwall 26 x includes an uppermost portion 26 xt of the lateral wall 26 x(i.e., a portion not removed by the blade 90) and the bottom surface 26xb of the second recess 26 xd (i.e., the portion formed by the blade90).

The uppermost portion 26 xt of the lateral wall 26 x is located higherthan the bottom surface 26 xb of the second recess 26 xd. Thus, thelight-shielding in the light-emitting device 3 is not substantiallyaffected by the second recess 26 xd in the lateral wall 26 x, while thelocation of the uppermost portion 26 xt of the lateral wall 26 x is ofimportance. Thus, in the light-emitting device 3 shown in FIG. 8B, thedetermination of the location of the upper surface 26 a of the lateralwall 26 as shown in FIG. 2 and the determination of the height 26 h ofthe lateral wall 26 shown in FIG. 3 can also be applied to the locationof the uppermost portion 26 xt of the lateral wall 26 z and to theheight 26 xh of the uppermost portion 26 xt of the lateral wall 26 x.

In the example shown in FIGS. 8A and 8B, the height 26 h of the lateralwall 26 formed in the step of providing the base member corresponds tothe height 26 xh of the uppermost portion 26 xt of the lateral wall 26 xin the light-emitting device ready for use. When the height of thelateral wall 26 can be placed with high precision in the step ofproviding the base member, retaining the height in the step ofselectively removing the light-transmissive layer allows forsufficiently accurate controlling of the height (that is, the height 26xh of the uppermost portion 26 xt of the lateral wall 26 x) of thelateral wall in terms of light-shielding.

In a top plan view of the light-emitting device 3 shown in FIG. 8B, aportion of the upper surface 26 xa of the lateral wall 26 x, which isthe bottom surface 26 xb of the second recess 26 xd can be seen in eachof the grooves 45 x. As described above, when the light-emitting device3 is used for a display device, adjacent light emitting parts can beseen separated from each other by corresponding portions of the bottomsurface 26 xb. The bottom surface 26 xb has a trace of the blade 90, inother words, the bottom surface 26 xb is roughened. Accordingly, theexternal light reflected at the bottom surface 26 xb toward the viewercan be reduced, so that a display with higher contrast ratio can beprovided.

Further, as shown in FIG. 5E, a very precise controlling is required tocontrol the depth 90 d of the blade 90 so as not to remove the upperportion 26 a of the lateral wall 26, while penetrating the coveringportion 400 x of the light-transmissive layer 400, in other words, whileremoving the entire of the covering portion 400 x in its thicknessdirection. On the other hand, it is advantageous, as shown in FIG. 8A,when the depth 90 d of the blade 90 is greater than the thickness 400 dof the covering portion 400 x because it allows the blade 90 penetratingthe entire depth of the covering portion 400 x while tolerating thevariation in the blade depth 90 d.

The example shown in FIG. 9A is similar to that in the example shown inFIG. 5E except the shape of the blade 91. The blade 91 shown in FIG. 9Ahas a peripheral cutting edge, which can reduce the stress applied tothe blade 91 at the time of removing the light-transmissive layer 400and the lateral wall 26.

The light-emitting device 4 shown in FIG. 9B exhibits similar effects asthat of the light emitting device 3 shown in FIG. 8B, such as incontrolling the height of the lateral wall in terms of light-shielding,reduction in reflecting external light toward the viewer, and toleratingthe variation in the blade depth. In particular, reduction in reflectingexternal light toward the viewer can be more significant than that inthe light emitting device 3 shown in FIG. 8B. The detail will bedescribed below.

As shown in FIG. 9B, the upper surface 26 ya of the lateral wall 26 yincludes an uppermost portion 26 yt of the lateral wall 26 y (i.e., aportion not removed by the blade 91) and a bottom surfaces 26 yb of asecond recess 26 yd (i.e., a portion formed by the blade 91). The bottomsurface 26 yb of the second recess 26 yd may have a cross sectionalshape corresponding to the shape of the cutting edge of the blade 91,e.g., a V-shaped cross-section.

In the light-emitting device 4 shown in FIG. 9B, as in thelight-emitting device 3 shown in FIG. 8B, the bottom surface 26 yb ofthe second recess 26 yd has a trace of the blade 91, in other words, thebottom surface 26 yb is roughened. Accordingly, the external lightreflected at the bottom surface 26 yb toward the viewer can be reduced.Further, in the light-emitting device 4 shown in FIG. 9B, the bottomsurface 26 yb is formed in a V-shape, so that external light incident onthe groove 45 y from above is not simply reflected back upward.

As described above, in the light-emitting device 4 shown in FIG. 9B, thebottom surface 26 yb of the second recess 26 yd of the upper surface 26ya of the lateral wall 26 y is roughened and sloped, so that externallight incident on the bottom surface 26 yb of the second recess 26 yd inthe groove 45 y is not simply reflected toward the opening of the groove45 y. Thus, a display with higher contrast ratio can be provided.

The covering portion 400 x may also be partially removed by using ablade 92 having inclined lateral surfaces to form a sharp cutting edge,for example, as shown in FIG. 10A. As the blade 91 shown in FIG. 9A, theblade 92 also has an outer peripheral cutting edge, which is sharperthan that of the blade 91. Although the blade width 92 w of the blade 92is greater than the width 26 w of the lateral wall 26, a portion of theblade 92 sinking into the lateral wall 26 is narrower than the width 26w of the lateral wall 26. Thus, the covering portion 400 x can bepartially removed as shown in FIGS. 10A and 10B.

The light-emitting device 5 shown in FIG. 10B has the same advantages(including reducing the stress applied to the blade during cutting,controlling the substantial height of the lateral wall, reducingexternal light reflection, and allowing some variation in the blade'spenetration depth) as the light-emitting device 4 shown in FIG. 9B.Further, in the light emitting device 5 shown in FIG. 10B, the sharperthe cutting edge of the blade 92, the narrower the width of the grooves45 z, allowing narrowing the interval between adjacent light emittingparts 10.

As described above, the grooves provided in the light emitting devicecan be formed with desired shapes and dimensions by appropriatelyselecting the blade edge angle and/or the blade width, and/or adjustingthe blade depth.

Variations

In the first embodiment, a method of manufacturing a light-emittingdevice 1 having a plurality of light emitting parts 10 is illustrated.The first embodiment can be modified to facilitate manufacturing alight-emitting device having a single light emitting part 10.

The steps of providing the base member, mounting the light emittingelements, and disposing the light-transmissive layer, may be performedas in the first embodiment.

In the step of partially removing the light-transmissive layer, as shownin FIG. 11A, a blade 90 or 91 having a blade width smaller than thewidth 26 w of the lateral wall 26 may be used. In this variation, thedepth 90 d or 91 d of the blade 90 or 91 is increased to penetratethrough the covering portion 400 x of the light-transmissive layer 400,the lateral wall 26, and the plate member 27. Accordingly, adjacentlight emitting parts 10 can be separated into individual light emittingdevices 6. Each light-emitting device 6 thus fabricated has a singlefirst recess 30, at least one light-emitting element 50 arranged in thefirst recess 30, and a single light-transmissive member 40 covering thefirst recess 30.

The light-emitting device and method of manufacturing the deviceaccording to the embodiments of the present invention can be preferablyapplied for displays and also for light sources for lighting, lightsources of backlights, and so forth.

Although the present disclosure has been described with reference toseveral exemplary embodiments, it is to be understood that the wordsthat have been used are words of description and illustration, ratherthan words of limitation. Changes may be made within the purview of theappended claims, as presently stated and as amended, without departingfrom the scope and spirit of the disclosure in its aspects. Although thedisclosure has been described with reference to particular examples,means, and embodiments, the disclosure may be not intended to be limitedto the particulars disclosed; rather the disclosure extends to allfunctionally equivalent structures, methods, and uses such as are withinthe scope of the appended claims.

The illustrations of the examples and embodiments described herein areintended to provide a general understanding of the various embodiments,and many other examples and embodiments may be apparent to those ofskill in the art upon reviewing the disclosure. Other embodiments may beutilized and derived from the disclosure, such that structural andlogical substitutions and changes may be made without departing from thescope of the disclosure. Additionally, the illustrations are merelyrepresentational and may not be drawn to scale. Certain proportionswithin the illustrations may be exaggerated, while other proportions maybe minimized. Accordingly, the disclosure and the figures are to beregarded as illustrative rather than restrictive.

One or more examples or embodiments of the disclosure may be referred toherein, individually and/or collectively, by the term “disclosure”merely for convenience and without intending to voluntarily limit thescope of this application to any particular disclosure or inventiveconcept. Moreover, although specific examples and embodiments have beenillustrated and described herein, it is to be appreciated that anysubsequent arrangement designed to achieve the same or similar purposemay be substituted for the specific examples or embodiments shown. Thisdisclosure may be intended to cover any and all subsequent adaptationsor variations of various examples and embodiments. Combinations of theabove examples and embodiments, and other examples and embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the description.

In addition, in the foregoing Detailed Description, various features maybe grouped together or described in a single embodiment for the purposeof streamlining the disclosure. This disclosure is not to be interpretedas reflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may be directed toless than all of the features of any of the disclosed embodiments. Thus,the following claims are incorporated into the Detailed Description,with each claim standing on its own as defining separately claimedsubject matter.

The above disclosed subject matter shall be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments which fall within thetrue spirit and scope of the present disclosure. Thus, to the maximumextent allowed by law, the scope of the present disclosure may bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing detailed description.

What is claimed is:
 1. A light-emitting device comprising: a base memberhaving a plurality of first recesses each defined by a bottom surfaceand lateral surfaces that are inner surfaces of a lateral wallseparating adjacent first recesses of the plurality of first recesses;at least one light-emitting element mounted in each of the plurality offirst recesses; and a plurality of light-transmissive members, eachhaving a flat upper surface and covering one of the plurality of firstrecesses, wherein the plurality of light-transmissive members areseparated from each other by the lateral wall separating the adjacentfirst recesses; and the upper surface of each of the plurality of lighttransmissive members is located higher than an uppermost portion of thelateral wall, wherein the base member comprises a substrate and thelateral wall, and in a cross-sectional view of each of the plurality offirst recesses, a virtual line passing through an edge of an uppersurface of the at least one light-emitting element and an edge of anupper surface of the lateral wall forms an angle of 0 to 5 degrees withrespect to an upper surface of the substrate.
 2. The light-emittingdevice according to claim 1, wherein the at least one light-emittingelement comprises a plurality of light-emitting elements and theuppermost portion of the lateral wall is located higher than an activelayer of any of the plurality of light-emitting elements.
 3. Thelight-emitting device according to claim 1, wherein the upper surface ofthe lateral wall is partially covered by portions of thelight-transmissive members.
 4. The light-emitting device according toclaim 1, wherein the upper surface of the lateral wall defines a secondrecess.
 5. The light-emitting device according to 1, wherein the lateralwall is of a black color or a nearly black, dark color.
 6. Thelight-emitting device according to claim 1, wherein a red light-emittingelement, a green light-emitting element, and a blue light-emittingelement are mounted in each of the plurality of first recesses.
 7. Thelight-emitting device according to claim 1, wherein the plurality offirst recesses are arranged in rows and columns, a number of the rowsand a number of the columns each being a power of two.
 8. Alight-emitting device comprising: a base member having a plurality offirst recesses each defined by a bottom surface and lateral surfacesthat are inner surfaces of a lateral wall separating adjacent firstrecesses of the plurality of first recesses; at least one light-emittingelement mounted in each of the plurality of first recesses; and aplurality of light-transmissive members, each having a flat uppersurface and covering one of the plurality of first recesses, wherein theplurality of light-transmissive members are separated from each other bythe lateral wall separating the adjacent first recesses; and the uppersurface of each of the plurality of light transmissive members islocated higher than an uppermost portion of the lateral wall, whereinthe upper surface of the lateral wall defines a second recess.
 9. Thelight-emitting device according to claim 8, wherein the at least onelight-emitting element comprises a plurality of light-emitting elementsand the uppermost portion of the lateral wall is located higher than anactive layer of any of the plurality of light-emitting elements.
 10. Thelight-emitting device according to claim 8, wherein the upper surface ofthe lateral wall is partially covered by portions of thelight-transmissive members.
 11. The light-emitting device according to8, wherein the lateral wall is of a black color or a nearly black, darkcolor.
 12. The light-emitting device according to claim 8, wherein a redlight-emitting element, a green light-emitting element, and a bluelight-emitting element are mounted in each of the plurality of firstrecesses.
 13. The light-emitting device according to claim 8, whereinthe plurality of first recesses are arranged in rows and columns, anumber of the rows and a number of the columns each being a power oftwo.
 14. Alight-emitting device comprising: a base member having aplurality of first recesses each defined by a bottom surface and lateralsurfaces that are inner surfaces of a lateral wall separating adjacentfirst recesses of the plurality of first recesses; at least onelight-emitting element mounted in each of the plurality of firstrecesses; and a plurality of light-transmissive members, each having aflat upper surface and covering one of the plurality of first recesses,wherein the plurality of light-transmissive members are separated fromeach other by the lateral wall separating the adjacent first recesses;and the upper surface of each of the plurality of light transmissivemembers is located higher than an uppermost portion of the lateral wall,wherein the lateral wall is of a black color or a nearly black, darkcolor.
 15. The light-emitting device according to claim 14, wherein theat least one light-emitting element comprises a plurality oflight-emitting elements and the uppermost portion of the lateral wall islocated higher than an active layer of any of the plurality oflight-emitting elements.
 16. The light-emitting device according toclaim 14, wherein the upper surface of the lateral wall is partiallycovered by portions of the light-transmissive members.
 17. Thelight-emitting device according to claim 14, wherein a redlight-emitting element, a green light-emitting element, and a bluelight-emitting element are mounted in each of the plurality of firstrecesses.
 18. The light-emitting device according to claim 14, whereinthe plurality of first recesses are arranged in rows and columns, anumber of the rows and a number of the columns each being a power oftwo.